In recent years, computer systems' performance and capabilities have continued to advance rapidly in light of various technological advances and improvements with respect to processor architecture and performance. In particular, central processing unit (CPU) speed has continued to improve significantly in the past several years. However, memory access speed has not improved as much compared with the CPU speed. Consequently, CPU operations and performance can be limited by memory access speed. To improve this situation, some CPUs employ high access speed memory (e.g., cache memory) to store some part of main memory (also called system memory) in order to improve memory access efficiency. Typically a CPU may need a cache memory having a size larger than 4 kbytes (KB) with high access speed to be located near the CPU. Such a cache memory is typically expensive and tends to require complicated design cache or memory controller circuit. Consequently, the use of such cache memory may negatively impact the CPU design itself and the overall cost of the CPU. Accordingly, there exists a need to improve CPU memory access efficiency without large size of high speed memory (cache) or complicated memory controller design.